Polymer optical waveguide and optical waveguide component

Abstract

A polymer optical waveguide includes a core having an end surface, and a cladding provided around the core and having a first surface, wherein a recess is formed in the first surface. The end surface is exposed inside the recess, and the end surface is located at a position deeper than the first surface.

What is claimed is: 
     
         1 . A polymer optical waveguide comprising:
 a core having an end surface; and   a cladding provided around the core and having a first surface, wherein:   a recess is formed in the first surface,   the end surface is exposed inside the recess, and   the end surface is located at a position deeper than the first surface.   
     
     
         2 . The polymer optical waveguide as claimed in  claim 1 , wherein the end surface is a convex surface. 
     
     
         3 . The polymer optical waveguide as claimed in  claim 1 , wherein:
 in a plan view from above in a direction perpendicular to the first surface, the end surface is separated from a sidewall surface of the recess and is located on an inner side of the sidewall surface.   
     
     
         4 . The polymer optical waveguide as claimed in  claim 1 , wherein the recess has a bottom surface including:
 the end surface, and   a second surface of the cladding,   wherein the second surface is continuous with the end surface.   
     
     
         5 . The polymer optical waveguide as claimed in  claim 1 , wherein:
 the recess has a sidewall surface, and   the end surface is continuous with the sidewall surface.   
     
     
         6 . The polymer optical waveguide as claimed in  claim 1 , wherein
 the core includes a first portion located inside the recess, and a second portion connected to the first portion, and   in a plan view from above in a direction perpendicular to the first surface, the second portion is located on an inner side of the first portion at a boundary between the first portion and the second portion.   
     
     
         7 . An optical waveguide component comprising:
 a substrate having a principal surface; and   the polymer optical waveguide according to  claim 1  provided on the principal surface.   
     
     
         8 . An optical waveguide component comprising:
 a substrate having a principal surface; and   the polymer optical waveguide according to  claim 2  provided on the principal surface.